1. Field of the Invention
This invention relates to a musical tone synthesizing apparatus which is used in the synthesis of the musical tones of plucked-string or struck-string instruments.
2. Prior Art
Devices which put into operation a model obtained by simulating the tone production mechanism of an acoustic musical instrument and thus synthesize the tones of the acoustic musical instrument are commonly known. Conventionally, devices which synthesize the tones of stringed musical instruments are known which have a construction in which a non-linear amplifying component which simulates the elastic characteristics of the strings is combined in a closed loop with a delaying circuit which has a delay interval corresponding to the harmonic cycle of the strings. In this type of musical tone synthesizing apparatus, this loop circuit is brought to a resonant state and a fixed signal is circulated in the loop circuit. Furthermore, the signal circulating in the loop is taken for use as the musical tone signal. This type of technology was disclosed in Japanese Patent Application, Laid-open publication no. Sho 63-40199, and U.S. Pat. No. 4,130,043.
In the conventional musical tone synthesizing apparatuses described above, in the case of a plucked-string instrument such as a guitar, for example, as the stiffness or shape of the pick change, the behavior of the string when plucked changes, so that differing tones are generated. Furthermore, in struck-string instruments such as pianos, as the hardness, etc., of the hammers change, differing musical tones are generated. However, in conventional musical tone synthesizing apparatuses, the state and action of the physical system in which the strings are excited, such as the stiffness and shape of the pick, the hardness of the hammers, etc., were not simulated, so that the musical tones could not be synthesized with fidelity.